The Allen-Bradley 1756-CN2RXT is a ControlNet redundant communication module (ControlLogix-XT series) used in the ControlLogix PLC system from Rockwell Automation. It provides high-speed, deterministic ControlNet communication and supports extended environmental temperature range (XT version) for harsh industrial applications.
This module is designed for mission-critical systems requiring redundant ControlNet networks, high reliability, and operation in extreme temperatures.
It is commonly used in oil & gas, offshore platforms, petrochemical plants, and other harsh industrial environments.
Technical Specifications
| Parameter | Details |
|---|---|
| Product Type | ControlNet Redundant Communication Module |
| Model | 1756-CN2RXT |
| System Compatibility | Allen-Bradley ControlLogix |
| Series | ControlLogix-XT (Extended Temperature) |
| Network Type | ControlNet |
| Communication Speed | 5 Mbps |
| Channels | Dual ControlNet ports (A/B redundancy) |
| Max Nodes | Up to 99 nodes |
| Max Connections | 128 Logix connections (+ reserved redundancy connections) |
| Data Transfer | Scheduled & unscheduled messaging |
| Backplane Interface | ControlLogix chassis backplane |
| Power Consumption | ~6.6 W |
| Current Draw | 1.3 A @ 5.1 V DC |
| Isolation Voltage | 30 V continuous |
| USB Port | 1 × USB diagnostic/programming port |
| ControlNet Cable | 1786-RG6 coaxial cable |
| Installation Type | Chassis slot-mounted module |
| Operating Temperature | -25°C to 70°C |
| Storage Temperature | -40°C to 85°C |
This module supports extended temperature operation for harsh environments, unlike standard CN2/CN2R models.
Physical Dimensions & Weight
- Dimensions (H × W × D): 55 mm × 218 mm × 179 mm
- Weight: ~0.293 kg
The module is designed as a single-slot ControlLogix module and fits in XT-compatible chassis.
Function in ControlLogix System
The 1756-CN2RXT is used to:
- Provide redundant ControlNet communication (A/B networks)
- Support deterministic real-time I/O updates
- Enable controller-to-controller communication
- Maintain communication integrity in harsh environments
- Support high-availability industrial control systems
- Operate in extended temperature conditions (XT design)
Recommended Related Models
- Allen-Bradley 1756-CN2R (standard redundant ControlNet module)
- Allen-Bradley 1756-CN2 (non-redundant ControlNet module)
- Allen-Bradley 1756-EN2T Ethernet communication module
- Allen-Bradley 1756-L7x / L8x ControlLogix controllers
- Allen-Bradley 1756-A5XT / A7XT chassis (XT systems)
